Rollup of 6 pull requests#57405

Merged

bors merged 14 commits intorust-lang:masterfrom

pietroalbini:rollup

Jan 7, 2019

Commits on Jan 2, 2019

remove outdated comment
mark-i-m
committed

Commits on Jan 3, 2019

Make CompileController thread-safe
Zoxc
committed

Commits on Jan 6, 2019

Provide the option to use libc++ even on all platforms
petrhosek
committed
use utf-8 throughout htmldocck
euclio
committed
Add duration constants
Stjepan Glavina
committed
Re-export constants from core into std
Stjepan Glavina
committed

Commits on Jan 7, 2019